Prime Minister Ranil Wickremesinghe's United National Party (UNP) won the elections as the largest party in a coalition known as the United National Front for Good Governance (UNFGG, see note). The UNFGG took 11 more seats than the opposition coalition, the United People's Freedom Alliance (UPFA), led by former President Mahinda Rajapakse. The UPFA includes the Sri Lanka Freedom Party (SLFP) which is headed by incumbent President Maithripala Sirisena. Despite belonging to an opposition coalition, some SLFP members opposed Mr. Rajapakse and allied themselves to the governing coalition, the UNFGG. During the elections, the major parties promised good governance, transparency, economic progress and stability in the country. On 21 August, Mr. Wickremasinghe was sworn in as the Prime Minister. Later that day, the UNP and the SLFP signed a Memorandum of Understanding to form a new government. The two parties agreed to work together for at least two years. The 46-member Cabinet, formed in September, comprises 33 ministers from the UNFGG and 13 ministers from the SLFP.

The 2015 elections were the first to be held under President Sirisena, the former health minister, who defeated the long-serving President Rajapaksa in presidential elections, held in January 2015. In keeping with the new President's electoral promise, Parliament passed the 19th amendment to the Constitution on 28 April 2015. In particular the amendment re-introduced a two-term limit for each President (lifted in 2010 under President Rajapaksa) and removed the President's power to dissolve Parliament until it has completed four-and-a-half years of its five-year term. Before the amendments, the President could dissolve Parliament after only one year.

Note:
The UNFGG included the UNP, Sri Lanka Muslim Congress (SLMC), Tamil Progressive Alliance (TPA), All Ceylon Makkal Congress (ACMC), Jathika Hela Urumaya (JHU) as well as SLFP members who opposed former President Rajapakse.